In a semiconductor device manufacturing process, semiconductor wafers (hereinafter referred to as “wafers”) as substrates are loaded into, e.g., a substrate conveying container called a closed-type FOUP (Front-Opening Unified Pod) in a shelf-like manner. Further, the wafers are transferred between semiconductor manufacturing apparatuses. Therefore, an opening/closing device for opening and closing a lid mounted on the side surface of a FOUP is provided in a wafer conveying port of a semiconductor manufacturing apparatus.
The opening/closing device is configured as follows. An opening is formed in a wall existing between a region in which the FOUP is placed and a wafer transfer region in which the wafers taken out from the FOUP are transferred. The periphery of the FOUP around the lid is brought into hermetic contact with the periphery of the opening of the opening. The opening is hermetically sealed by a cover member at the side of the wafer transfer region. The lid of the FOUP is removed by an opening/closing mechanism provided in the cover member. At this time, a seal member made of resin or rubber is installed between the cover member and the opening in order to, e.g., restrain an atmospheric gas existing in a FOUP transfer region from flowing into the wafer transfer region through a lid opening/closing region. When removing the lid of the FOUP, the region hermetically sealed by the seal member is initially evacuated and then supplied with a clean gas such as a nitrogen (N2) gas or the like, thereby substituting the atmospheric gas existing in the hermetically sealed region with the clean gas. The cover member can move up and down between a lid detaching/attaching position and a shelter position in which the cover member waits when the wafers are taken out from the FOUP to the wafer transfer region. Moreover, the cover member can move back and forth between an up/down movement position and a position in which the cover member hermetically seals the opening.
In this regard, there is a demand for a technology capable of reducing the number of mechanisms provided in an opening/closing device, and consequently reducing the cost of the opening/closing device while restraining a generation of dust and particles from the mechanisms of the opening/closing device. More specifically, a demand is increased for developing a technology that omits a mechanism (particularly, a drive shaft) for advancing and retracting the opening/closing device. As one example of this technology, a device in which the surface sealed by an opening/closing device is inclined with respect to a vertical axis so that a transfer port can be sealed only by the up/down operation of the opening/closing device is provided.
However, if the surface sealed by the opening/closing device is inclined as stated above, the opening/closing device makes a sliding contact with a seal member. Thus, the seal member is easily worn out or unevenly worn out. It is therefore necessary to frequently perform maintenance services of the device (replacement of the seal member), which results in an increased maintenance cost.